1. FESTINGER, L., SCHACHTER, S., BACK, K.Social Pressures in Informal Groups: A study of a housing community. New York, Harper, I950.
2.
2. HELSON, H."Adaptation Level as a Frame of Reference for Prediction of Psychological Data", Amer. J. Psychol., I947, 60, 1-29.
3.
3. KENDALL, M. G.The Advanced Theory of Statistics (3rd ed.). London, Griffin and Co. Ben Willerman and Leonard Swanson
4.
4. KRECH, D., and CRUTCHFIELD, R. S.Theory and Problems of Social Psychology, New York, McGraw-Hill, I948.
5.
5. OLDS, E. G., "Distributions of sums of squares of rank differences for small numbers of individuals", The Annals of Mathematical Statistics, 1938, 9, 133-I48.